Four years of big crops in the U.S. and the world have brought some economic pain for farmers in the form of prices that, in many cases, are below the cost of production. Low prices are serving to stimulate demand, though, and they will ultimately be self-curing.With USDA’s pending 12 September release of the monthly WASDE, futures trading this week will no doubt be dominated by expectations of its fresh yield and production estimates for U.S. corn and soybeans. The discussions over the size of this year’s presumably record crops will continue until at least November. By that time, it is assumed that harvests will be far enough along to make the market comfortable with its yield and production assumptions. The September WASDE is a just a st...